A lens barrel includes front and rear sub-lens groups; front and rear sub-lens group frames for supporting the front and rear sub-lens groups, respectively; a lens frame shift mechanism for causing the front sub-lens group frame and the rear sub-lens group frame to move relative to each other to obtain the mutually close position and the mutually distant position; a first lens group positioning surface provided on the front sub-lens group frame for positioning the front sub-lens group by contacting with a portion of a rear surface of the front sub-lens group; and a second lens group positioning surface provided on the rear sub-lens group frame for positioning the front sub-lens group by contacting with a portion of a front surface of the rear sub-lens group.